Sequentially coded electrical locking means

ABSTRACT

A switch operated electrical lock is disclosed. A group of switches is provided, a number of which must be operated in an exact sequence to operate the lock. The operation of any single switch out of sequence requires all of the switches to be reset and the switching operation to be repeated.

O Unlted States Patentv 1151 3,662,226 Tonkowich et al. [451 May 9, 1972 s41 SEQUENTIALLY CODED ELECTRICAL 1,775,924 9/1930 Aikman ..317/134 LOCKING MEANS 1,923,968 8/1933 Chase ..317/134 2,561,076 21951 T ..3171 72 Inventors: William Tonkowich; John A. Meditz, both 3 192 448 41965 22 1 gi l sg gfi 'g f 3,311,794 3/1967 Holland et al. ..317/137 [73] Assignee: Satetech, lnc., Fairfield, NJ. primary Emminehqfl Hix 22 Filed: Mar. 5 1971 Attorney-Norman N. Holland A switch operated electrical lock is disclosed. A group of 56 switches is provided, a number of which must be operated in [58] Fieid 317/137 5 35 an exact sequence to operate the lock. The operation of any I 6 single switch out of sequence requires all of the switches to be reset and the switching operation to be repeated. [56] References cued 12 Claims, 2 Drawing Figures 1 UNITED STATES PATENTS 1,724,792 8/1929 Chase et a1. ..317/134 SEQUENTIALLY CODED ELECTRICAL LOCKING MEANS BACKGROUND OF THE INVENTION The present invention relates to an electric lock andmore particularly to an electric lock which is keyed or operated by closing a number ofswitches in an exact sequence.

A number of keyless locks have beenused both to eliminate the key itself and to provide improved security. In certain systems using a remote control position such as auto locks, door locks, etc., the locking element itself includes an electric solenoid or other electrically operated latch device. In these and other keyless systems, electric coding or keying means are convenient and appropriate. I

In order to be fully practical for locks of this type, the electrical coding or keying must be highly reliable. To achieve the needed degree of reliability and at the same time to obtainan electric system of reasonable cost and ease of manufacture, the system must have a simple design and be composed of a minimum number of elements, each of which is itself inexpensive and reliable.

The improved electric coding or keying circuit of the present invention provides improved reliability using a minimum number of components and at the same time is tamperproof and provides a high degree of security.

SUMMARY OF THE INVENTION Basically, the system utilizes only two electrical relays plus a number of standard switches or an equivalent transistor or vacuum tube circuit. In order to operate or key the systems, a

number of switches, selected from a larger group of switches, must be operated in an exact sequence. Any digression from the. sequence requires the system to becompletely reset and re-operated.

Accordingly, an object of the present invention is to provide an improved electric locking device.

Another object of the invention is to provide an improved electric switch coded lock which cannot be tampered with or otherwise operated without knowledge of the correct combination.

Another object of the present invention is to provide a more secure and more simplified switch coded electrical locking means. I

Other and further objects of the invention will be obvious upon an understanding of the illustrative embodiment about to be described or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.

BRIEF DESCRIPTION OF THE DRAWING A preferred embodiment of the invention has been chosen for purposes of illustration and description and is shown in the accompanying drawings, forming a part of the specification, wherein:

FIG. 1 is a schematic of a preferred embodiment of the circuit of the invention; and

FIG. 2 is a schematic of an alternate embodiment using transistors in place of relays of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A detailed description of the encoding system follows wherein a sequential operation of a series of X switches must be taken from a larger group" of Y switches. Y must be greater than "or equal to X. The type of switches required for the sequential operation is a push-to-lock, push-to-release switch with atleast a SPDT and a SPST-NO contact arrangement. FIG. 1 illustrates the Y group as having ten switches and X as being fiveswitches. All the SPST normally open contacts 1-10 of the Y switches are wired in parallel as shown. The switches not in the sequence, i.e., the Y minus Xswitches, have normally closed contacts 1'-5 wired in series as shown. The

SPDT contacts 6'-10' of the X switches that are in the sequence are wired as shown. The common terminal 10" of the last switch in the sequence is connectedthrough the normally closed contacts C11 of relay 11 to the coil of relay 12. The nonnally open terminal 10" of the last switch in the sequence is connected to one side of the normally open contacts C12A of relay 12. The other side of the normally open relay contacts C12A is connected to the coil of an output relay 13.

One side of the SPST contacts 1-10, which are all in parallel, is connected to the coil of relay 11 through the normally closed contact C12B of relay 12.

It should be noted that contacts 1 and 1', 2 and 2', 3 and 3', etc. operate together so that closing any of contact l-S opens the corresponding one of contacts l'5' and closing any one of contacts 6-10 causes one of the double throw contacts '-l0 to be thrown.

When the power on/off switch 14 is turned on, all the SPST switch contacts l-10 are open andall the SPDT switch concircuit to the relay 12 coil is broken and the relay ll coil is energized. Once relay coil 11 is energized, the relay contact C11 is opened and it is impossible to energize the relay l2 coil or to supply power to the output relay 13 through the normally open contacts C12A.

In order to reset the relay 1] and 12 contacts C11, C12A and C128 so that whenever a correct sequential operation occurs an output also results, it is necessary to return all switches to their initial or released position before proceeding with the sequential operation. Returning all switches to their initial position de-energizes the relay 11 coil and re-energizes relay 12 coil. When all the switches are returned to their initial position, relay contact C11 closes completing a path from the power supply 15 to the relay 12 coil. When relay l2 coil is reenergized, relay contact C12B re-opens and relay contact C12A re-closes.

For a proper sequential operation, the path of continuity between the power supply 15 and the relay 12 coil is maintained only by transferring the continuous path to the common terminal of the next switch in the sequence. When switch contact 6' is closed, it transfers the power to contact 7' and allows the switching of power to contact 8'. This procedure continues until the common terminal of the last switch contact 10' in the sequence has power transmitted to it to permit the power to be transferred to the switch output terminal 10". During this switching, power is seen to be continually supplied to the relay 12 coil keeping its contact C12A closed and its contact C open.

In the event of power interruption to the relay 12 coil due to a non-sequential operation of the switches, relay 11 will be energized causing the output to become isolated from the power supply.

Once the relay 13 receives power from the switches, it closes contact C13A and remains independent of the switches as long as the on/ofi switch 14 remains on. Normally closed contact C138 on relay 13 opens, turning oh the warning light 16. Once the sequence has been performed, therefore, a mechanical reset switch can be depressed, releasing all the switches and returning their contacts 1-10 and 1-l0' to their initial positions.

Relay 12 has an operate voltage that is greater than relay 11. That is, if the coil voltage across both relays 11 and 12 were to be increased at the same time, relay 11 would always operate before relay 12.

This situation could exist if all the sequence switches were depressed before the on/off switch 14 was in the on position. In this event, the relay 12 coil would be receiving current through the normally closed contacts C11 of relay l1 and conversely, therelay 11 coil would be receiving current through a the normally closed contacts C12B of relay 12 and a race" condition would then exit. One way to insure that relay 11 always wins this "race" is to have the relay contacts C11 open. This can be accomplished by having a lower operate voltage on relay 11 than for relay 12. The coil resistance for relays 11 and 12 is preferably the sameso that the switching of the relays due to improper sequential coding cannot be easily detected by monitoring the supply current.

For greater security against a sophisticated thief or intruder, the output relay 13 should have a set of normally closed con-' tacts C13C that supply power to an electrical-mechanical buzzer 17. The buzzer sounds continuously until the combination is performed properly. Additional normally open contacts C13D may be provided so that after proper sequencing, the common switch release button must be operated before the buzzer stops. Contacts C1315 and C131- are provided to operate the electrically controlled door latches or motor fuel cut-off valves or car ignitions, etc. The buuer 17 also has a psychologically disturbing quality which may add to the frustration of the would-be intruderand it obscures any audible clicking of the relays whenever the sequence is performed incorrectly. The electrical transients of the relays changing state due to an improper sequential operation of the switches are also obscured by the electrical transients caused by the buuer 17. Diodes 18, 19 and 20 suppress relay coil back emfs.

When the off-on switch 14 is opened, the relay '13 opens and the system returns to its original state. A by-pass line including a normally open switch 21 may be added to permit operation of the system using only switch 14. As soon as switch 21 is again opened, the system returns to its protective sequenced control. I

AN ALTERNATE EMBODIMENT FIG. 2 illustrates a transistor equivalent of the solenoid operated relay embodiment of FIG. 1. The relays 11 and 12 of the relay embodiment have been replaced by the solid state circuitry containing transistors 21, 22 and 23.

The physical switching of the ten switches having contacts 31-40 and 31'-40' is the same as the electrical relay embodiment described above. When the ignition switch 41 is closed, all contacts 31-40 and 31'-40' are in the position shown. Transistor 22 is on because current is flowing through the switch contacts 31'-40 and through resistor'42 into the base of transistor 22. Transistor 22 keeps transistor 21 off whenever the proper sequence is performed. When the fifth switch in the sequence with contacts 40' is thrown, transistor 23 is on and the output relay 44 is energized. This opens, contacts C44A to turn off the signal light 46, closes latching contact C448 and the load or lock control contact C44C.

In the event of a non-sequential operation of the switches for contacts 31-40 and 31 '-40' the path of continuity between the battery 45 and the resistor 42 through contacts 3l'-40' is broken and transistor 22 goes off. I

Since at least one switch has been depressed in order to per form a non-sequential operation thereby closing at least one contact 31-40, there now exists a path of continuity from the battery 45 to resistor 43. Since transistor 22 is off, transistor 21 turns on and inhibits any further effort to turn on transistor 22 until all switches are returned to their original starting position. When transistor 22 is off so is transistor 23. The output relay 44 is isolated from the fifth switch contact 40 in the sequence whenever transistors 22 and 23 are 05. In the event power is applied to both resistors 43 and 42 simultaneously, as in thevevent of depressing the five active sequence switches having contacts 36'40' before closing the ignition switch 41,

resistor 47 is greater than resistor 48 and capacitor 49 is greater than capacitor 50 to give a faster voltage rise on transistor 21 so that transistor'21 will go on before transistor 22 in all cases thus preventing the energizing of the output relay 44 with an unauthorized sequential operation.

Diode 51 blocks current when transistor 22 is oil and transistor 21 is on. Diode 52 balances the voltage drop in diode 51. Diode 53 protects transistor 23 from reverse current flow and diode 54 insolat'es the output contacts from current when the by-pass switch 55 is closed. Diode 56 suppresses back emf. across the relay 44 coil.

The by-pass switch 55 included in this circuit has the same function as the above described by-pass switch 21. It is seen that this switch applies battery power through the relay 44 contact C448 to the coil of relay 44 so that the systems may be operated using the on-ofi switch 41 as long as the proper sequence has previously been inserted. The by-pass switch 55 is used to permit operation of the locked device in temporary situations as, for example, where a protected vehicle may be left in a parking lot. Once the by-pass switch 55 and the on-ofi' switch .41 are both opened, the system may then only be operated thereafter by again inserting the correct switch sequence. I

It will .be seen that an-improved switch operated electrical lock has been provided which is tamperproof and which is at the same time reliable and relatively simple. The improved electrical lock is of particular value in systems where the locking or latching device itself is remotely positioned and is electrically actuated. Such uses include car locks, door locks, as well as a variety of other locking situations.

As various changes may be made in the form, construction and arrangementsof the parts herein without departing from the spirit and scope of the invention and without sacrificing any of its advantages, it is ,to be understood that all matter herein is to be interpreted as illustrative and not in a limiting sense.

Having thus described our invention, we claim:

1. An improved sequentially operated electric locking means comprising the combination of: I

a first electrically actuated switching means controlling a first normally open and a second normally closed current interrupting means; a second electrically actuated switching means controlling a third normally closed current interrupting means; a source of electric power;

a plurality of manually operated'switches having first con tacts connectedto form a normally-closed serial circuit including said third current interrupting means between said electric power and said first switching means;

at least a portion of said switches having their contacts arranged for sequential operation for supplying said electric.

power to said first current interrupting meanswithout opening said serial circuit;

said plurality of switches each having second normally open switch contacts coupled for operation with said first switch contacts; 1

said second contacts being coupled in parallel with one another; and

said parallel coupled contacts forming a serial connection 7 with said second current interrupting means between said 1 source of power and said second electrically actuated switching means.

2. The locking means as claimed in claim 1 in which said electrically actuated switching means both comprise solenoid actuated relays.

3. The locking means as claimed in claim 1 in which said electrically actuated switching means both comprise transistors.

4. The locking means as claimed in claim 1 which further comprises an electrically actuatedoutput device coupled to said first current interrupting means.

5. The locking means as claimed in claim 4'which further comprises a manually operated by-pass switch coupled between the source of electric power and said output device.

6. An improved sequentially operated electric locking means comprising the combination of: I

a first solenoid actuated relay having a first normally open contact and a second normally closed contact;

a second solenoid actuated relay having a third normally closed contact;

a source of electric power;

a plurality of manually operated switches having first contacts connected to form a normally closed serial circuit including said third contact between said source of electric power and said first relay;

at least a portion of said switches having their contacts arranged for sequential operation for supplying said electric power to said first contact without opening said serial cir cuit;

said plurality of switches each having a second normally open switch contact coupled for simultaneous operation with said first switch contacts;

said second switch contacts being coupled in parallel with one another; and

said parallel coupled switch contacts forming a serial connection with said second relay contact between said source of electric power and said second relay.

7. The locking means as claimed in claim 6 which further comprises a third solenoid actuated relay coupled to said first relay contact.

8. The locking means as claimed in claim 7 which further comprises a normally open contact on said third relay coupling the third relay solenoid to the source of electric voltage as a latching means.

9. The locking means as claimed in claim 8 which further comprises a manually operated by-pass switch coupled between said source of electric power and said normally open contact on said third relay.

10. An improved sequentially operated electric locking means comprising the combination of:

a first transistor with base and collector and emitter;

a second transistor with base and collector and emitter;

a third transistor with base and collector and emitter;

a source of electric power;

a plurality of manually operated switches having first contacts connected to form a normally closed serial circuit between said source of electric power and the base of said second transistor;

at least a portion of said switches having their contacts arranged for sequential operation for supplying said electric power to the collector of said third transistor without opening said serial circuit;

said plurality of switches each having second normally open switch contacts coupled for operation with said first switch contacts;

said second contacts being coupled in parallel with one another and connecting said source of electric power with the base of said first transistor;

said first and second transistors having their emitters grounded;

the collector of said first transistor being coupled to the base of said second transistor;

the collector of said second transistor being coupled to the base of said third transistor; and

the third transistor collector being coupled to an electrically operated output device.

11. The locking means as claimed in claim 10 in which said output device comprises a solenoid actuated relay having normally open contacts coupled to said source of electric power.

12. The locking means as claimed in claim 11 which further 

1. An improved sequentially operated electric locking means comprising the combination of: a first electrically actuated switching means controlling a first normally open and a second normally closed current interrupting means; a second electrically actuated switching means controlling a third normally closed current interrupting means; a source of electric power; a plurality of manually operated switches having first contacts connected to form a normally closed serial circuit including said third current interrupting means between said electric power and said first switching means; at least a portion of said switches having their contacts arranged for sequential operation for supplying said electric power to said first current interrupting means without opening said serial circuit; said plurality of switches each having second normally open switch contacts coupled for operation with said first switch contacts; said second contacts being coupled in parallel with one another; and said parallel coupled contacts forming a serial connection with said second current interrupting means between said source of power and said second electrically actuated switchinG means.
 2. The locking means as claimed in claim 1 in which said electrically actuated switching means both comprise solenoid actuated relays.
 3. The locking means as claimed in claim 1 in which said electrically actuated switching means both comprise transistors.
 4. The locking means as claimed in claim 1 which further comprises an electrically actuated output device coupled to said first current interrupting means.
 5. The locking means as claimed in claim 4 which further comprises a manually operated by-pass switch coupled between the source of electric power and said output device.
 6. An improved sequentially operated electric locking means comprising the combination of: a first solenoid actuated relay having a first normally open contact and a second normally closed contact; a second solenoid actuated relay having a third normally closed contact; a source of electric power; a plurality of manually operated switches having first contacts connected to form a normally closed serial circuit including said third contact between said source of electric power and said first relay; at least a portion of said switches having their contacts arranged for sequential operation for supplying said electric power to said first contact without opening said serial circuit; said plurality of switches each having a second normally open switch contact coupled for simultaneous operation with said first switch contacts; said second switch contacts being coupled in parallel with one another; and said parallel coupled switch contacts forming a serial connection with said second relay contact between said source of electric power and said second relay.
 7. The locking means as claimed in claim 6 which further comprises a third solenoid actuated relay coupled to said first relay contact.
 8. The locking means as claimed in claim 7 which further comprises a normally open contact on said third relay coupling the third relay solenoid to the source of electric voltage as a latching means.
 9. The locking means as claimed in claim 8 which further comprises a manually operated by-pass switch coupled between said source of electric power and said normally open contact on said third relay.
 10. An improved sequentially operated electric locking means comprising the combination of: a first transistor with base and collector and emitter; a second transistor with base and collector and emitter; a third transistor with base and collector and emitter; a source of electric power; a plurality of manually operated switches having first contacts connected to form a normally closed serial circuit between said source of electric power and the base of said second transistor; at least a portion of said switches having their contacts arranged for sequential operation for supplying said electric power to the collector of said third transistor without opening said serial circuit; said plurality of switches each having second normally open switch contacts coupled for operation with said first switch contacts; said second contacts being coupled in parallel with one another and connecting said source of electric power with the base of said first transistor; said first and second transistors having their emitters grounded; the collector of said first transistor being coupled to the base of said second transistor; the collector of said second transistor being coupled to the base of said third transistor; and the third transistor collector being coupled to an electrically operated output device.
 11. The locking means as claimed in claim 10 in which said output device comprises a solenoid actuated relay having normally open contacts coupled to said source of electric power.
 12. The locking means as claimed in claim 11 which further comprises normally open latching contacts on said relay coupled between said source of electric power and the relay solenoid. 